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All Journal Indonesian Journal of Forestry Research Jurnal Penelitian Hutan dan Konservasi Alam Forest and Society Indonesian Journal of Forestry Research
Ishak Yassir
Balai Penelitian Teknologi Sumber Daya Alam-Samboja, East Kalimantan
Agriculture, Biological Sciences & Forestry Environmental Science Social Sciences

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SOIL ORGANIC MATTER DYNAMICS UPON SECONDARY SUCCESSION IN IMPERATA GRASSLAND, EAST KALIMANTAN, INDONESIA Yassir, Ishak; Buurman, Peter
Indonesian Journal of Forestry Research Vol 2, No 1 (2015): Indonesian Journal of Forestry Research
Publisher : Secretariat of Forestry Research and Development Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20886/ijfr.2015.2.1.43-53

Abstract

Soil organic matter (SOM) dynamics upon secondary succession in Imperata grassland was studied by stable carbon isotope analysis. The data of litter and soil samples of twenty plots in four different stages of successions were compared. These different stages were represented by plots that were; (1) burnt 3 years before sampling/observation (Imperata grassland), (2) burnt 9 years before sampling /observation, (3) secondary forest (≥15 years) and (4) primary forest. The results showed that isotopic signatures of all soil horizons of the regeneration stages were statistically different from those of the primary forest. The A-horizon under the 3-years Imperata plot still contained 23% forest (C3) carbon, and this fraction increased to 51% in the-B-horizon. In the 9-years plot and in the secondary forest, the C3 carbon in the A-horizon increased to 51% and 96%, respectively.  In the topsoil, the loss of C4-C between the 3-years and the 9-years plot was significant, while it appeared negligible in the AB-horizon. The strong decay in the topsoil under Imperata grassland may be due to the rather high carbohydrate content of the SOM, which is considered easily decomposable. Further research is needed especially to explore the relation between carbon stocks and chemical composition of SOM. Such insight may help to better understand and predict soil carbon changes in relation to climate and vegetation change.
PENGARUH DOSIS PUPUK ORGANIK TERHADAP PERTUMBUHAN MAHONI (Swietenia macrophylla King) PADA LAHAN ALANG-ALANG DI SAMBOJA, KALIMANTAN TIMUR Yassir, Ishak; Omon, R. Mulyana
Jurnal Penelitian Hutan dan Konservasi Alam Vol 4, No 4 (2007): Jurnal Penelitian Hutan dan Konservasi Alam
Publisher : Pusat Penelitian dan Pengembangan Hutan

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Abstract

ABSTRAK Penelitian pengaruh pemberian pupuk organik terhadap pertumbuhan tanaman mahoni (Swietenia macrophylla King) telah dilakukan di Kawasan Rehabilitasi Hutan Samboja Lestari. Tujuan penelitian ini adalah untuk mendapatkan informasi dosis pupuk organik optimal terhadap pertumbuhan mahoni pada lahan kritis yang ditumbuhi alang-alang. Empat dosis pupuk organik (1 kg, 2 kg, 3 kg, dan 4 kg) yang dicoba dalam percobaan ini. Rancangan percobaan yang digunakan adalah acak lengkap berblok yang diulang sebanyak lima kali. Setiap perlakuan ditanam sebanyak lima tanaman. Jumlah tanaman yang diamati sebanyak 125 tanaman. Hasil penelitian menunjukkan bahwa perlakuan dosis pupuk organik tidak berbeda nyata terhadap persen  hidup  dan  pertumbuhan  tinggi.  Tetapi,  pemberian  dosis  lebih  dari  satu  kg  pupuk  organik menyebabkan banyak tanaman yang mati hingga sebesar 35 % dibandingkan dengan kontrol. Namun,  untuk pertumbuhan tinggi perlakuan dosis sebanyak dua kg telah memberikan pertumbuhan yang optimal.
DIVERSITY OF PLANT COMMUNITIES IN SECONDARY SUCCESSION OF IMPERATA GRASSLANDS OF EAST KALIMANTAN, INDONESIA Yassir, Ishak; Arbainsyah, Arbainsyah
Indonesian Journal of Forestry Research Vol 1, No 2 (2014): Indonesian Journal of Forestry Research
Publisher : Secretariat of Forestry Research and Development Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20886/ijfr.2014.1.2.139-149

Abstract

Regeneration of Imperata grassland areas is becoming increasingly important, both to create new secondary forest and to recover the original biodiversity. We studied the diversity of plant communities in secondary succession of Imperata grasslands using 45 subplots of 9 linear transects (10 m x 100 m). Data was collected and all stems over 10 cm dbh were identified  , the Importance Values Index (IVI) for all trees were calculated, saplings and seedlings were counted  and analysed, and soil samples were taken and analysed. Results showed that  after more than 10 years of regeneration, 65 families were encountered consisting of 164 species, which were dominated by Vernonia arborea Buch.-Ham, Vitex pinnata L., Macaranga gigantea (Reichb.f. & Zoll.) Muell.Arg., Symplocos crassipes C.B. Clarke, Artocarpus odoratissimus Miq., and Bridelia glauca Blume. The effects of regeneration, from Imperata grassland to secondary forest, on soil were the strongest in the A-horizon where an increase in carbon, N content, and pH were observed. Our result shows that Imperata grasslands appear to be permanent because of frequent fires and human interferences and so far few efforts have been made to promote sustainable rehabilitation. If protected from fire and other disturbances, such as shifting cultivation, Imperata grassland will grow and develop into secondary forest.
Why is Multi-Business Forestry Needed to Overcome the Low Performance of Forestry Governance and Food Security in Indonesia? Suryanto, Suryanto; Nurrochmat, Dodik Ridho; Tarigan, Suria Darma; Siregar, Iskandar Zulkarnaen; Yassir, Ishak; Silalahi, Mangarah; Mansur, Irdika; Harisson, Rhett D.; Wahyudi, Agus; Abdulah, Lutfy
Forest and Society Vol. 8 No. 2 (2024): DECEMBER
Publisher : Forestry Faculty, Universitas Hasanuddin

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24259/fs.v8i2.32529

Abstract

The 0.6% contribution of the forestry sector to GDP is considered very low despite 64.1% of Indonesia's land area being allocated as forests. Most of the 64.8% production forest allocated is not yet optimized for strengthening national food security, in which Indonesia is ranked 65th in the world. Therefore, an innovative forest management system is needed to synergize timber and non-timber production. This paper presents a multi-business forestry (Mb-F) implementation strategy analyzed through a dynamic system-based multi-criterion decision-making tool named Super Model Mb-F (SM Mb-F). SM Mb-F is built based on a causal loop diagram (CLD), which describes the dynamic relationship between land typology suitability and decisions related to the type of business, commodities, land use area, workload, and financing for many variables relating to 5M business principles and sustainability. Results showed that CLD formulated in 280 sub-models in a total of 4,764 decision variables with an error deviation of 6.4%. The SM Mb-F simulation on two sample concession units produces a projected increase in wood supply, employment, and state revenue, plus the provision of new functions such as food, NTFP, and environmental services. These benefits are obtained by business feasibility. Assuming that gradually until 2030, the Mb-F can be implemented in 32% of Indonesia's production forests, then by 2045, it is projected that there will be an increase in wood production by 296.8%, state revenue by 654.3%, and labor absorption by 985.7%, as well as adding food production up to 19.36 M tons. This is because the land use efficiency of the current operation of forest concessions following the Annual Allowable Cut (AAC) under the selective cutting and replanting system in Indonesia (TPTI) is only about 3% of the total area of forest concession. Assuming the cutting cycle is 35 years, timber could be extracted in 1/35 of the total forest concession area. Implementing Mb-F will significantly improve the land use efficiency from about 3% to 90%.  The Mb-F will also restrain the rate of decline in carbon stocks, which is deeper if governance is still under the BAU scenario. This research suggests further global research, emphasizing the importance of innovative models for sustainable forestry governance and food security worldwide.
SOIL ORGANIC MATTER DYNAMICS UPON SECONDARY SUCCESSION IN IMPERATA GRASSLAND, EAST KALIMANTAN, INDONESIA Yassir, Ishak; Buurman, Peter
Indonesian Journal of Forestry Research Vol. 2 No. 1 (2015): Indonesian Journal of Forestry Research
Publisher : Association of Indonesian Forestry and Environment Researchers and Technicians

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59465/ijfr.2015.2.1.43-53

Abstract

Soil organic matter (SOM) dynamics upon secondary succession in Imperata grassland was studied by stable carbon isotope analysis. The data of litter and soil samples of twenty plots in four different stages of succession were compared. These different stages were represented by plots that were; (1) last burned 3 years before sampling (Imperata grassland), (2) last burned 9 years before, (3) a secondary forest (≥15 years) and (4) a primary forest. Result showed that isotopic signatures of all soil horizons of the regeneration stages were statistically different from those of the primary forest. The A-horizon under the 3-years Imperata plot still contained 23% forest (C3) carbon, and this fraction increased to 51% in the-B-horizon. In the 9-years plot and in the secondary forest, the C3 carbon on the A-horizon increased to 51% and 96%, respectively. In the topsoil, the loss of C4-C between the 3-years and the 9-years plot was significant, while it appeared negligible in the AB-horizon. The strong decay in the topsoil under Imperata grassland may be due to the rather high carbohydrate content of the SOM, which is considered easily decomposable. Further research is needed especially to explore the relation between carbon stocks and chemical of SOM composition. Such insight may help to better understand and predict soil carbon changes in relation to climate and vegetation change.
DIVERSITY OF PLANT COMMUNITIES IN SECONDARY SUCCESSION OF IMPERATA GRASSLANDS IN SAMBOJA LESTARI, EAST KALIMANTAN, INDONESIA Yassir, Ishak
Indonesian Journal of Forestry Research Vol. 1 No. 2 (2014): Indonesian Journal of Forestry Research
Publisher : Association of Indonesian Forestry and Environment Researchers and Technicians

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59465/ijfr.2014.1.2.139-149

Abstract

Regeneration of Imperata grassland areas is becoming increasingly important, both to create new secondary forest and to recover the original biodiversity. The diversity of plant communities in secondary succession of Imperata grasslands was studied using 45 subplots of 9 linear transects (10 m x 100 m). Data was collected and all stems over 10 cm dbh were identified, the Importance Values Index (IVI) for all trees were calculated, saplings and seedlings were counted and analysed, and soil samples were taken and analysed. Results showed that after more than 10 years of regeneration, 65 families were encountered consisting of 164 species, which were dominated by Vernonia arborea Buch.-Ham, Vitex pinnata L., Macaranga gigantea (Reichb.f. & Zoll.) Muell.Arg., Symplocos crassipes C.B. Clarke, Artocarpus odoratissimus Miq., and Bridelia glauca Blume. The effects of regeneration, from Imperata grassland to secondary forest, on soil were the strongest in the A-horizon where an increase in carbon, N content, and pH were observed. Our result shows that Imperata grasslands appear to be permanent because of frequent fires and human interferences and so far few efforts have been made to promote sustainable rehabilitation. If protected from fire and other disturbances, such as shifting cultivation, Imperata grassland will grow and develop into secondary forest.
Co-Authors Agus Wahyudi Arbainsyah Arbainsyah Dodik Ridho Nurrochmat Harisson, Rhett D. Irdika Mansur ISKANDAR ZULKARNAEN SIREGAR Lutfy Abdulah Peter Buurman R. Mulyana Omon, R. Mulyana Silalahi, Mangarah Suria Darma Tarigan Suryanto Suryanto